Add example based on custom_textures.rs

This commit is contained in:
John-Mark Allen 2021-06-21 22:31:18 +01:00 committed by Jack Spira
parent 87baa92b98
commit d1df09dab4
2 changed files with 285 additions and 0 deletions

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@ -17,6 +17,7 @@ memoffset = "0.6.4"
[dev-dependencies]
glutin = "0.26.0"
imgui-winit-support = { version = "0.7.1", path = "../imgui-winit-support" }
image = "0.23"
[features]
# Features here are used to opt-out of compiling code that depends on certain

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@ -0,0 +1,284 @@
//! Example showing the same functionality as
//! `imgui-examples/examples/custom_textures.rs`
use std::{io::Cursor, time::Instant};
use glow::HasContext;
use image::{jpeg::JpegDecoder, ImageDecoder};
use imgui::{im_str, Condition};
use imgui_glow_renderer::{RendererBuilder, StateBackupCsm};
mod utils;
const LENNA_JPEG: &[u8] = include_bytes!("../../resources/Lenna.jpg");
fn main() {
let (event_loop, window) = utils::create_window("Custom textures", glutin::GlRequest::Latest);
let (mut winit_platform, mut imgui_context) = utils::imgui_init(&window);
let gl = utils::glow_context(&window);
let mut ig_renderer = RendererBuilder::new()
.with_context_state_manager(StateBackupCsm::default())
.with_texture_map(imgui::Textures::<glow::Texture>::default())
.build_borrowing(&gl, &mut imgui_context)
.expect("failed to create renderer");
let textures_ui = TexturesUi::new(&gl, &mut ig_renderer.texture_map);
let mut last_frame = Instant::now();
event_loop.run(move |event, _, control_flow| {
*control_flow = glutin::event_loop::ControlFlow::Wait;
match event {
glutin::event::Event::NewEvents(_) => {
let now = Instant::now();
imgui_context
.io_mut()
.update_delta_time(now.duration_since(last_frame));
last_frame = now;
}
glutin::event::Event::MainEventsCleared => {
winit_platform
.prepare_frame(imgui_context.io_mut(), window.window())
.unwrap();
window.window().request_redraw();
}
glutin::event::Event::RedrawRequested(_) => {
unsafe { gl.clear(glow::COLOR_BUFFER_BIT) };
let ui = imgui_context.frame();
textures_ui.show(&ui);
winit_platform.prepare_render(&ui, window.window());
let draw_data = ui.render();
ig_renderer
.render(&gl, &draw_data)
.expect("error rendering imgui");
window.swap_buffers().unwrap();
}
glutin::event::Event::WindowEvent {
event: glutin::event::WindowEvent::CloseRequested,
..
} => {
*control_flow = glutin::event_loop::ControlFlow::Exit;
}
glutin::event::Event::LoopDestroyed => {
ig_renderer.destroy(&gl);
}
event => {
winit_platform.handle_event(imgui_context.io_mut(), window.window(), &event);
}
}
});
}
struct TexturesUi {
generated_texture: imgui::TextureId,
lenna: Lenna,
}
impl TexturesUi {
fn new(gl: &glow::Context, textures: &mut imgui::Textures<glow::Texture>) -> Self {
Self {
generated_texture: Self::generate(gl, textures),
lenna: Lenna::load(gl, textures),
}
}
/// Generate dummy texture
fn generate(
gl: &glow::Context,
textures: &mut imgui::Textures<glow::Texture>,
) -> imgui::TextureId {
const WIDTH: usize = 100;
const HEIGHT: usize = 100;
let mut data = Vec::with_capacity(WIDTH * HEIGHT);
for i in 0..WIDTH {
for j in 0..HEIGHT {
// Insert RGB values
data.push(i as u8);
data.push(j as u8);
data.push((i + j) as u8);
}
}
let gl_texture = unsafe { gl.create_texture() }.expect("unable to create GL texture");
unsafe {
gl.bind_texture(glow::TEXTURE_2D, Some(gl_texture));
gl.tex_parameter_i32(
glow::TEXTURE_2D,
glow::TEXTURE_MIN_FILTER,
glow::LINEAR as _,
);
gl.tex_parameter_i32(
glow::TEXTURE_2D,
glow::TEXTURE_MAG_FILTER,
glow::LINEAR as _,
);
gl.tex_image_2d(
glow::TEXTURE_2D,
0,
glow::RGB as _,
WIDTH as _,
HEIGHT as _,
0,
glow::RGB,
glow::UNSIGNED_BYTE,
Some(&data),
)
}
textures.insert(gl_texture)
}
fn show(&self, ui: &imgui::Ui) {
imgui::Window::new(im_str!("Hello textures"))
.size([400.0, 400.0], Condition::FirstUseEver)
.build(ui, || {
ui.text(im_str!("Hello textures!"));
ui.text("Some generated texture");
imgui::Image::new(self.generated_texture, [100.0, 100.0]).build(ui);
ui.text("Say hello to Lenna.jpg");
self.lenna.show(ui);
// Example of using custom textures on a button
ui.text("The Lenna buttons");
{
ui.invisible_button(im_str!("Boring Button"), [100.0, 100.0]);
// See also `imgui::Ui::style_color`
let tint_none = [1.0, 1.0, 1.0, 1.0];
let tint_green = [0.5, 1.0, 0.5, 1.0];
let tint_red = [1.0, 0.5, 0.5, 1.0];
let tint = match (
ui.is_item_hovered(),
ui.is_mouse_down(imgui::MouseButton::Left),
) {
(false, _) => tint_none,
(true, false) => tint_green,
(true, true) => tint_red,
};
let draw_list = ui.get_window_draw_list();
draw_list
.add_image(
self.lenna.texture_id,
ui.item_rect_min(),
ui.item_rect_max(),
)
.col(tint)
.build();
}
{
ui.same_line();
// Button using quad positioned image
ui.invisible_button(im_str!("Exciting Button"), [100.0, 100.0]);
// Button bounds
let min = ui.item_rect_min();
let max = ui.item_rect_max();
// get corner coordinates
let tl = [
min[0],
min[1] + (ui.frame_count() as f32 / 10.0).cos() * 10.0,
];
let tr = [
max[0],
min[1] + (ui.frame_count() as f32 / 10.0).sin() * 10.0,
];
let bl = [min[0], max[1]];
let br = max;
let draw_list = ui.get_window_draw_list();
draw_list
.add_image_quad(self.lenna.texture_id, tl, tr, br, bl)
.build();
}
// Rounded image
{
ui.same_line();
ui.invisible_button(im_str!("Smooth Button"), [100.0, 100.0]);
let draw_list = ui.get_window_draw_list();
draw_list
.add_image_rounded(
self.lenna.texture_id,
ui.item_rect_min(),
ui.item_rect_max(),
16.0,
)
// Tint brighter for visiblity of corners
.col([2.0, 0.5, 0.5, 1.0])
// Rounding on each corner can be changed separately
.round_top_left(ui.frame_count() / 60 % 4 == 0)
.round_top_right((ui.frame_count() + 1) / 60 % 4 == 1)
.round_bot_right((ui.frame_count() + 3) / 60 % 4 == 2)
.round_bot_left((ui.frame_count() + 2) / 60 % 4 == 3)
.build();
}
});
}
}
struct Lenna {
texture_id: imgui::TextureId,
size: [f32; 2],
}
impl Lenna {
fn load(gl: &glow::Context, textures: &mut imgui::Textures<glow::Texture>) -> Self {
let decoder = JpegDecoder::new(Cursor::new(LENNA_JPEG)).expect("could not create decoder");
let (width, height) = decoder.dimensions();
let lenna_image = {
let mut bytes = vec![0; decoder.total_bytes() as usize];
decoder
.read_image(&mut bytes)
.expect("unable to decode jpeg");
bytes
};
let gl_texture = unsafe { gl.create_texture() }.expect("unable to create GL texture");
unsafe {
gl.bind_texture(glow::TEXTURE_2D, Some(gl_texture));
gl.tex_parameter_i32(
glow::TEXTURE_2D,
glow::TEXTURE_MIN_FILTER,
glow::LINEAR as _,
);
gl.tex_parameter_i32(
glow::TEXTURE_2D,
glow::TEXTURE_MAG_FILTER,
glow::LINEAR as _,
);
gl.tex_image_2d(
glow::TEXTURE_2D,
0,
glow::RGB as _,
width as _,
height as _,
0,
glow::RGB,
glow::UNSIGNED_BYTE,
Some(&lenna_image),
)
}
Self {
texture_id: textures.insert(gl_texture),
size: [width as _, height as _],
}
}
fn show(&self, ui: &imgui::Ui) {
imgui::Image::new(self.texture_id, self.size).build(ui);
}
}